Benign vascular proliferations in previously irradiated skin

Gingival acquired lymphangiectasia as a long-term effect of post-oncology intervention: A 20-year institutional audit

Background

Gingiva is a keratinised mucosa akin to the skin and is exposed in all modalities of treatment of oral cancer. Acquired lymphangiectasia are acquired dilatations of lymphatic channels secondary to an external cause. They are extremely rare in the oral cavity despite that oral cancers are treated with different treatment modalities.

Methods

The archives of the Oral and Maxillofacial Pathology Department of our institute were retrospectively reviewed from 2001 to 2021. Of the 9566 cases of oral biopsies, 4596 were confirmed cases of oral cancer including salivary gland carcinoma. These cases were followed up for the presence of post-neoplastic and post-therapeutic gingival lesions.

Results

Of the 4596 patients, <10% patients reported recurrence or new primary of squamous cell carcinoma in the gingiva. Two patients were histopathologically diagnosed with acquired lymphangiectasia of gingiva after 12 years following surgery and radiation therapy as treatment for oral squamous cell carcinoma and mucoepidermoid carcinoma, which has been described in our report for the first time in the literature.

Conclusion

Even though acquired lymphangiectasia of gingiva is very rare, lymphatic malformations should be included in the clinical differential diagnosis of post-therapeutic gingival proliferative pathologies in order to ensure appropriate treatment and prevent over-diagnosis of this benign condition.

Caspase 3 in dying tumor cells mediates post-irradiation angiogenesis

Cytotoxic radiotherapy unfavorably induces tumor cells to generate various proangiogenic substances, promoting post-irradiation angiogenesis (PIA), which is one of major causes of radiotherapy failure. Though several studies have reported some mechanisms behind PIA, they have not yet described the beginning proangiogenic motivator buried in the irradiated microenvironment. In this work, we revealed that dying tumor cells induced by irradiation prompted PIA via a caspase 3 dependent mechanism. Proteolytic inactivation of caspase 3 in dying tumor cells by transducing a dominant-negative version weakened proangiogenic effects in vitro and in vivo. In addition, inhibition of caspase 3 activity suppressed tumor angiogenesis and tumorigenesis in xenograft mouse model. Importantly, we identified vascular endothelial growth factor (VEGF)-A as a downstream proangiogenic factor regulated by caspase 3 possibly through Akt signaling. Collectively, these findings indicated that besides acting as a key executioner in apoptosis, caspase 3 in dying tumor cells may play a central role in driving proangiogenic response after irradiation. Thus, radiotherapy in combination with caspase 3 inhibitors may be a novel promising therapeutic strategy to reduce tumor recurrence due to restrained PIA.

Post-radiotherapy vascular proliferations in mammary skin: A clinicopathologic study of 11 cases

BACKGROUND

Post-radiotherapy atypical vascular lesions (AVL) in mammary skin show significant clinical and histopathologic overlap with well-differentiated angiosarcoma (AS) and pose a considerable diagnostic and managerial challenge when encountered.

OBJECTIVE

We review Stanford's experience with diagnosing AVL and formulate a clinicopathologic approach to these lesions.

METHODS

We performed a clinicopathologic study on 11 cases that were initially diagnosed as AVL and examined whether there are specific clinical or histopathologic features that delineate AVLs from well-differentiated AS.

RESULTS

Clinically, all patients were women with a mean age of 68.1 years, had a history of infiltrating breast carcinoma, and were treated by excision with postoperative radiation therapy. All lesions were located in mammary skin within the prior radiation field. The clinical presentation included erythema, telangiectasias, papules, plaques, and nodules. All patients were diagnosed with AVL on initial biopsy. Six patients showed no recurrence or progression of disease following incomplete excision with no further therapy (3/6) or re-excision with negative margins (3/6). The remaining 5 patients were shown to have AS in the re-excision specimen. The patients diagnosed with AS were older and had a shorter interval from radiation as compared to those who did not experience an adverse outcome. Histologically, all initial biopsy specimens were transected and were characterized by complex, anastomosing vascular proliferations with dilated spaces. Each case was morphologically evaluated according to the AVL criteria of Fineberg and Rosen. Three cases met all of the criteria for AVL, and these patients showed no progression of disease. The remaining cases met most but not all diagnostic criteria for AVL and showed some features of AS, but fell short of a definitive diagnosis of AS, including the 5 cases that were subsequently diagnosed as angiosarcoma.

LIMITATIONS

This retrospective study utilized a small number of cases from a single consultation service; therefore, some inherent selection bias may exist.

CONCLUSION

We could not identify unequivocal clinical or histologic criteria that allows for a sharp separation between AVL and AS. Dermatologists and pathologists need to be aware of the overlap between AVL and well-differentiated AS and all patients who receive a diagnosis of AVL should undergo complete excision with close clinical follow-up and biopsy of any new lesions.

Reactive Angioendotheliomatosis in Association with a Well-Differentiated Angiosarcoma

A 55-year-old white female with a complex medical history including mixed connective tissue disease and peripheral vascular disease developed a group of red-purple papules on her proximal medial thigh that was followed, five months later, by the development of a large violaceous patch. She reported a history of radiation to this site (for melanoma) during her childhood. She was admitted to the hospital with a presumptive diagnosis of cellulitis, but failed to respond to antibiotics. A biopsy was performed and demonstrated a well-differentiated angiosarcoma arising in conjunction with reactive angioendotheliomatosis. Excision of the lesion was performed, and fifteen months of follow-up have shown no recurrence or metastasis.